This section provides background information related to the present disclosure and is not necessarily prior art.
In an attempt to reduce the quantity of undesirable matter (e.g., NOx, hydrocarbons, carbon monoxide, and/or particulate matter) discharged to the atmosphere during internal combustion engine operation, a number of exhaust aftertreatment devices have been developed. Typical aftertreatment systems for combustion engine exhaust may include an oxidation catalyst (e.g., a diesel oxidation catalyst or DOC), a particulate filter (e.g., a diesel particulate filter or DPF), a selective catalytic reduction (SCR) system, and/or other aftertreatment components.
Aftertreatment systems may include a particulate sensor mounted within an exhaust gas passageway. Such particulate sensors have been positioned downstream of the particulate filter and are typically used in conjunction with an onboard diagnostics system to detect a failure of the particulate filter. Therefore, unless the particulate filter has been cracked or otherwise damaged, these particulate sensors are exposed to exhaust gas having virtually no particulate matter. In the event of a cracked particulate filter, the particulate sensors are typically only exposed to very small amounts of particulate matter. Accordingly, typical particulate sensors are not designed to withstand prolonged exposure to exhaust gas with a high particulate matter concentration.